Spyder 3 Elite - periodic ambient light check - what does it do?

Started Jun 5, 2011 | Discussions thread
Xipper
Regular MemberPosts: 407
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Re: Spyder 3 Elite - periodic ambient light check - what does it do?
In reply to Dubcat, Jun 6, 2011

The fact that there is no printed manual with a product in 2011 doesn't mean there isn't a manual to be read.

When I am in Spyder 3 Elite there is a "Help" option on the top of my screen. Opening that I quickly find the following topics around ambient light checking:

Measure Ambient Light

Usual Setting

There is no user input at this screen.

The Purpose of This Step

This advises the user that the application will now measure the ambient room lighting.

The Long Answer

The ambient light level will be used to set the display's brightness target value. This value will also determine that room light level is expected by Spyder3 Utility, as it monitors your room lighting over time.

Ambient Light Analysis

Usual Setting

Click on "Accept Suggested Settings" and continue with your calibration.

The Purpose of This Step

This step presents an analysis of your surrounding lighting conditions based on the measurement taken of those conditions. These settings are recommended for best calibration under your current conditions. You may choose to adjust your ambient light levels and remeasure, to obtain more desirable results.

The Long Answer

This analysis identifies the ambient light condition as one of five levels:

Very Low

Moderately Low

Medium

High

Very High

For each level, the analysis provides:

A description
Suggested steps to take
Suggested calibration target values

The recommended responses to respective ambient light levels 1 through 5 are as follows:

Very Low: appropriate for prepress image editing. Calibrate the display to a White Luminance level of 85-100 cd/m^2* and a White Point of 5000K (warm white) to compensate for the eye's cooler response at low light levels. LCD monitors (including laptops) can be used in this situation as well as CRT displays.

Moderately Low: dim, but appropriate for photo image editing. Calibrate the display to a White Luminance level of 125-150 cd/m^2 and a White Point of 5800K (slightly warm white) to compensate for the eye's slightly cooler response at moderately low light levels. LCD monitors (including laptops) can be used in this situation as well as very bright CRT displays.

Medium: appropriate for typical photo editing. Calibrate the display to a White Luminance level of 175-200 cd/m^2 and a White Point of 6500K (medium white) to compensate for the eye's moderate color response at medium light levels. Only LCD monitors (including laptops) can be used in this situation.

High: uncontrolled, not recommended for color critical work. Lower the ambient light if possible, otherwise use a monitor hood and calibrate the display to the maximum White Luminance it can produce and a White Point of 6500K or higher.

Very High: uncontrolled, not recommended for any color managed work. If you must work in these conditions use a monitor hood, umbrella or photographer's cloak and calibrate the display to the maximum White Luminance it can produce and a White Point of 6500K or higher.

CRT monitors should be used only at levels 1 and 2 since most large CRTs cannot achieve a White Luminance over 125 cd/m^2. LCD monitors with limited White Luminance should also be used only at levels 1 and 2.

Only LCD monitors should be used at level 3 and even then, some LCD monitors and many laptops cannot achieve the 175 cd/cm^2 needed for good viewing in those conditions.

If your monitor cannot achieve the recommended White Luminance level then you should lower the ambient light level to a range that is compatible with your monitor.

Critical color work requires an environment where the ambient light is consistent and at low to moderate levels.

Advanced Topic: Surround

Another area worthy of attention is the monitor Surround. This is the area of the room that your eyes see in their peripheral view while you are looking at the monitor. The Surround should be smooth, neutral in color and dimly lit.

If the Surround is brightly colored or brightly lit this will influence your perception of color and tone on the monitor. Viewing the same image with a different Surround condition may result in a different perception of the image. Including exterior windows in the Surround area causes variable influences on the eye, as well as glare and eye fatigue, and should be avoided for any long-term or color-sensitive work. Covering the wall behind the monitor (including any windows it may contain) with an opaque, medium gray cloth is the best solution to situations where the wall color, brightness, and windows, cannot be otherwise controlled.

Advanced Topic: Luminance and White Point

Each ambient light level has a recommended White Luminance that is based on keeping monitor brightness high enough for good perception of the full display range, and avoiding White Point adaptation by the eye to whites in the Surround, instead of on the monitor. If the monitor is not bright enough (or conversely, the ambient light is too bright), room lighting will reduce the eye's acuity and ability to distinguish shadow detail on screen. If there are bright areas in the Surround brighter than the white of the screen, the eye may adapt to the White Point of the surround, instead of the display, causing the display to appear both dim and off color.

Each ambient light level has a recommended White Point that is based on the eye's differential response to color with increasing luminance. In darker conditions, the Rods in the eye play a larger part in vision. The blue cast the Rods incorporate into vision mean that under low light conditions, a warmer monitor White Point is required for the eye to perceive color equivalently. This is why under Dim ambient conditions, with a low monitor luminance level, a White Point of 5000K is recommended. This effect continues up to or beyond the Medium ambient level, with increased White Point recommendations to match.

cd/m^2 is a measurement of the amount of light a device emits. cd/m^2 is an abbreviation for candelas per meter squared.

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